1. Field of the Invention
The present invention relates to a disc recliner for a vehicle seat assembly that allows pivotal adjustment of a seat back relative to a seat cushion. More particularly, the present invention relates to a continuous disc recliner having a release feature to quickly adjust a seat back to an easy-entry position or a fold flat position.
2. Description of Related Art
Automotive vehicles typically include one or more seat assemblies having a seat cushion and a seat back for supporting a passenger above a vehicle floor. The seat assembly is commonly mounted to the vehicle floor by a seat track assembly to allow sliding fore and aft adjustment of the seat assembly for passenger comfort. It is also common that the seat back is operatively coupled to the seat cushion by a recliner assembly to allow pivotal adjustment of the seat back relative to the seat cushion.
One well known type of recliner assembly includes a pair of continuous disc recliners that operatively couple the seat back to the seat cushion. A typical prior art continuous disc recliner includes a fixed plate secured to the seat cushion and a movable plate secured to the seat back and rotatably coupled to the fixed plate. The fixed plate is formed to include an outer profile having a plurality of outward-facing teeth and the movable plate is formed to include an inner profile having a plurality of inward-facing teeth. The outward-facing teeth have at least one less tooth than the inward-facing teeth. A drive mechanism is disposed between the movable and fixed plates and is operable for urging the movable plate to rotate relative to the fixed plate. The drive mechanism includes a cam and a pair of wedges that define an eccentric element. The eccentric element creates an eccentricity between the movable and fixed plates which presses a portion of the inward and outward-facing teeth together at an engagement point. When the cam is rotated in a first direction, the wedges are driven in the first direction causing a direction of the eccentricity to shift, thereby shifting the engagement point of the inward and outward-facing teeth. The shifting of the engagement point manifests itself as a wobbling rotational movement of the movable plate in the first direction, thereby tilting or reclining the seat back in a rearward direction. When the cam is rotated in a second direction, the wedges are driven in the second direction causing the direction of the eccentricity to shift, thereby shifting the engagement point of the inward and outward-facing teeth. The shifting of the engagement point manifests itself as a wobbling rotational movement of the movable plate in the second direction, thereby tilting the seat back in a forward direction. The seat back is maintained in a desired seating position due to friction between the inward and outward-facing teeth at the engagement point as well as friction between the drive mechanism and the fixed and movable plates.
One drawback of continuous disc recliners is the inability of providing quick adjustment or “dumping” of the seat back through a large seat back angle to an easy-entry position or a fold flat position overlying the seat cushion. In order to pivot the seat back to the easy-entry position or the fold flat position, continuous disc recliners must be actuated through the entire range of adjustment. While continuous disc recliners offer very good fine adjustment of the seat back, the longer actuation time to move the seat back through the large seat back angle is undesirable. In certain instances, an external release mechanism is provided to disconnect the seat back from the continuous disc recliner to allow the seat back to freely pivot to the easy-entry position or the fold flat position.
It is desirable therefore to provide a continuous disc recliner having a release mechanism to quickly pivot a seat back to an easy-entry position or a fold flat position.